The magnetization was measured as a function of decreasing field on se
veral polycrystalline hexaferrites that are potentially useful as micr
owave or millimeterwave materials, because of their low dielectric los
s. The materials are partially oriented by compaction in a magnetic fi
eld or hot-forging. The observed magnetization vs. field dependence is
shown to agree with a theoretical model, when allowance is made for t
he distribution of misalignment angles, crystalline anisotropy, and po
rosity.